The present invention relates to cable ties.
Cable ties, also known as harnessing devices, are well known in the art and are commonly used to bundle a plurality of objects, such as cables. Cable ties typically comprise an elongated strip of material, such as plastic, having a head at one end, a tail at the other end and either teeth or rungs disposed along the length of the strip. Feeding the tail of the tie through the head results in the tie taking the shape of a loop with the tail engaging and being locked in position by a pawl inside the head, the tail being incapable of removal once it is inserted in the head.
As an example of one type of cable tie, in U.S. Pat. No. 5,642,554 to S. C. Sorensen et al, there is disclosed a cable tie having an enhanced locking engagement between a pawl and ratchet teeth on a tongue. The cable tie includes an elongated tongue and a locking head having a movable pawl that is hinged at one side of an opening in the locking head across the opening from an abutment surface for locking engagement with a first set of ratchet teeth on one broad side of the tongue when the tip of the tongue has been inserted through the opening and teeth on the abutment surface for locking engagement with a second set of ratchet teeth on the other broad side of the tongue when the tip of the tongue has been inserted through the opening, and in which the side of the pawl including the pawl teeth converges toward the opposite side of the pawl in the direction of insertion, locking engagement is enhanced by the locking surface of at least one pawl tooth extending toward the apex of such tooth at an angle inclined toward the direction of insertion for locking engagement with a tooth of the first set of ratchet teeth; and by the locking surface of at least one of the first set of ratchet teeth extending toward the apex of such tooth at an angle inclined away from the direction of insertion for locking engagement with a pawl tooth.
As another example of another type of cable tie, in U.S. Pat. No. 5,636,412 to F. Lodi et al, there is disclosed a substantially permanent, fixed-circumference, non-abrasive binding device for gathering and binding plural articles, including a locking head, a tail, and an elongate strap therebetween. The head and tail ends include cooperative locking means for securing the tail end in the locking head. The tail end includes outwardly projecting tail barbs to facilitate pulling the tail end through the locking head, and subsequently to facilitate engagement of locking barbs located on the end of the strap with barb stops located in the head. The score line is preformed across the tail end at a point between the locking barbs and the tail end, to provide for a break--any tail which can be removed after engagement of the locking barbs with the barb stops in the head. Upon engagement of the locking barbs with the barb stops, the score line is at a position slightly inside of the locking head so that no sharp or abrasive edge will be exposed after the tail end is broken off.